Verify API
Easily validate customers across the world at scale. Our patented 2FA technology helps you protect against fraud, build trust, and increase conversion across multiple channels—no telecom or security experience required. Plus, you’ll only pay for successful verifications.

Verify V2
Our enhanced Verify V2 API is now available. Start using our new authentication channels now!
Verify V2
Our enhanced Verify V2 API is now available. Start using our new authentication channels now!
Learn moreSee how Verify helps businesses like yours succeed
Prevent Fraud
Use up-to-date intelligence on phone numbers to detect potentially fraudulent transactions. The second step in 2-factor authentication easily minimizes fraud with an extra layer of security.Multiple Authentication Channels
In addition to SMS and Voice (TTS), authentication can be accomplished over WhatsApp, email and Silent Authentication, allowing you to authenticate your end-users where they prefer.Scale Your Deployments Globally
Whether you have customers in one country or hundreds of countries around the world, Verify takes care of all the heavy lifting so you can focus on your business.Customizable
Empower your clients to tailor the failover sequence to other channels, and generate and manage their own PINs.Only Pay for Successful Authentications
Efficiency and effectiveness matter. Only pay when your customers successfully verify their accounts.






Authentication Channels
SMS
Send one-time passwords (OTP) via the convenience of a text! Deliver SMS using approved sender IDs that are compliant with local rules and regulations.Voice
Text-to-speech (TTS) adds the personal touch of a human voice to your authentication workflow. Use TTS as a back-up when delivery of SMS is challenged.
Silent Authentication
Streamline verifications to just a few seconds, without requiring any user input by using Silent Authentication. Learn moreAcquire genuine customers anywhere in the world
Easily add a layer of protection by using a phone number to authenticate new and existing customers.- A single API offers a secure full two-factor authentication solution
- Bring your own number! Or, we can provide numbers for your authentication flow. Works with any phone number—no additional hardware or apps required
We do the heavy lifting for you, including sender ID management, OTP generation, failover, and fraud monitoring
Ensure one-time passwords (OTP) are delivered in accordance with country requirements
Protect your business from scammers
Prevent expensive unauthorized transactions while delivering a better experience.- Trigger step-up authentication only for those numbers suspected of being fraudulent
- Use up-to-date phone number intelligence to detect illegitimate transactions

Eradicate unsolicited messages more effectively
Block botnets and bulk account creation via frictionless phone verification for mobile users.- Suppress spam
- Minimize personal information sharing
- Give every user a unique identifier via their phone
- Confidently grow your application’s audience

Provide convenience without compromise
Ensure safe access by delivering time-limited, single-use authorization codes with passwordless authentication.- Let users gain instant and secure access to your app with just their phone
- Works with any type of phone line anywhere in the world—with a single API
- Pay only when users successfully access your application
Get smarter fail-safe, reliable delivery, and tailor-made messaging
Global Text-to-Speech (TTS)
TTS in languages to ensure you reach clients all over the world.Intelligent failover
Automatically resend PIN codes via voice (TTS) to customers through one API request—without additional code.Adaptive Routing™
Optimize delivery by proactively re-routing messages around congestion.Flexible implementation
Verify can be tested in minutes and implemented globally in a matter of hours. Choose from two models: Verify Success and Verify Conversion.See how businesses like yours are using Vonage APIs today